Can you tell me what you are using to prep the leather for when it is a little dried out (not just dirty)? Our couches look pretty good but were at a 7,500 ft elevation in Durango near sunny windows for 10 years. They are a bit faded and dry. I'd like to enrich their "Saddle" color to original but it would seem that some treatment is needed first to soften the leather. Any thoughts on this?